Endoscopic surgical clip applier with clip retention

ABSTRACT

An apparatus for application of surgical clips to body tissue is provided and includes a handle assembly; a shaft assembly including a housing extending distally from the handle assembly and defining a longitudinal axis; a plurality of surgical clips disposed within the shaft assembly; a jaw mounted adjacent a distal end portion of the shaft assembly, the jaw being movable between an open spaced-apart condition and a closed approximated condition; and a pusher bar reciprocally disposed within the housing of the shaft assembly and being detachably connectable to the housing of the shaft assembly, the pusher bar being configured to load a distal-most surgical clip into the jaws during distal movement and remain connected to the housing of the shaft assembly and in a distally advanced position during an approximation of the jaws.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. Ser. No.12/539,121, filed Aug. 11, 2009, which claims the benefit of andpriority to U.S. Provisional Application Ser. No. 61/092,790 filed onAug. 29, 2008, the entire contents of which are incorporated herein byreference.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical clip appliers and, moreparticularly, to a novel endoscopic surgical clip applier.

2. Background of Related Art

Endoscopic staplers and clip appliers are known in the art and are usedfor a number of distinct and useful surgical procedures. In the case ofa laparoscopic surgical procedure, access to the interior of an abdomenis achieved through narrow tubes or cannulas inserted through a smallentrance incision in the skin. Minimally invasive procedures performedelsewhere in the body are often generally referred to as endoscopicprocedures. Typically, a tube or cannula device is extended into thepatient's body through the entrance incision to provide an access port.The port allows the surgeon to insert a number of different surgicalinstruments therethrough using a trocar and for performing surgicalprocedures far removed from the incision.

During a majority of these procedures, the surgeon must often terminatethe flow of blood or another fluid through one or more vessels. Thesurgeon will often apply a surgical clip to a blood vessel or anotherduct to prevent the flow of body fluids therethrough during theprocedure. An endoscopic clip applier is known in the art for applying asingle clip during an entry to the body cavity. Such single clipappliers are typically fabricated from a biocompatible material and areusually compressed over a vessel. Once applied to the vessel, thecompressed clip terminates the flow of fluid therethrough.

Endoscopic clip appliers that are able to apply multiple clips inendoscopic or laparoscopic procedures during a single entry into thebody cavity are described in commonly-assigned U.S. Pat. Nos. 5,084,057and 5,100,420 to Green et al., which are both incorporated by referencein their entirety. Another multiple endoscopic clip applier is disclosedin commonly-assigned U.S. Pat. No. 5,607,436 to Pratt et al., thecontents of which is also hereby incorporated by reference herein in itsentirety. These devices are typically, though not necessarily, usedduring a single surgical procedure. U.S. patent application Ser. No.08/515,341 now U.S. Pat. No. 5,695,502 to Pier et al., the disclosure ofwhich is hereby incorporated by reference herein, discloses aresterilizable surgical clip applier. The clip applier advances andforms multiple clips during a single insertion into the body cavity.This resterilizable clip applier is configured to receive and cooperatewith an interchangeable clip magazine so as to advance and form multipleclips during a single entry into a body cavity. One significant designgoal is that the surgical clip be loaded between the jaws without anycompression of the clip from the loading procedure. Such bending ortorque of the clip during loading often has a number of unintendedconsequences. Such compression during loading may alter slightly thealignment of the clip between the jaws. This will cause the surgeon toremove the clip from between the jaws for discarding the clip.Additionally such preloading compression may slight compress parts ofthe clip and change a geometry of the clip. This will cause the surgeonto remove the compressed clip from between the jaws for discarding theclip.

Endoscopic or laparoscopic procedures are often performed remotely fromthe incision. Consequently, application of clips may be complicated by areduced field of view or reduced tactile feedback for the user at theproximal end of the device. It is therefore desirable to improve theoperation of the instrument by providing indication to the user of afiring of an individual clip, the depletion of the clips contained inthe loading unit, or any other surgical event. It is also desirable toprovide a surgical clip applier that promotes a successful loading ofthe clip and that wedges the jaws of the surgical clip applier open,then loads the clip between the jaws in order to prevent any damage orexcessive compression of the clip and prevents compression of the jawson the clip before firing.

SUMMARY

The present disclosure relates to novel endoscopic surgical clipappliers.

According to an aspect of the present disclosure, an apparatus forapplication of surgical clips to body tissue is provided. The apparatusincludes a handle assembly; a shaft assembly extending distally from thehandle assembly and defining a longitudinal axis; a plurality ofsurgical clips disposed within the shaft assembly; a jaw mountedadjacent a distal end portion of the shaft assembly, the jaw beingmovable between an open spaced-apart condition and a closed approximatedcondition; and a pusher bar reciprocally disposed within the shaftassembly, the pusher bar being configured to load a distal-most surgicalclip into the jaws while the jaws are in the open condition and remainin contact with the loaded surgical clip during an approximation of thejaws.

The pusher bar may include a pusher formed at a distal end thereof. Thepusher may have a narrow profile for contacting the loaded surgicalstaple at a single location. The pusher may define a plane that isoriented substantially orthogonal to a plane of the loaded surgicalstaple.

The apparatus may further include a connector plate reciprocallydisposed within the shaft assembly. The connector plate may beselectively connected to the pusher bar. In use, during an initialdistal movement of the connector plate, the pusher bar may be distallyadvanced and during a further distal movement of the connector plate theconnector plate may be disconnected from the pusher bar.

The pusher bar may include a first spring clip supported thereon forselectively engaging a feature of the shaft assembly when the pusher baris in an advanced position for selectively maintaining the pusher bar inthe advanced position. The pusher bar may further include a secondspring clip supported thereon for selectively engaging a first featureof the connector plate. The first feature of the connector plate mayselectively disengage from the second spring clip following the initialdistal movement of the connector plate.

The apparatus may further include an advancer plate reciprocallydisposed within the shaft assembly. The advancer plate may include atleast one fin selectively engageable by a shoulder of the pusher bar. Inuse, the shoulder of the pusher bar may engage the at least one fin ofthe advancer plate during a distal and a proximal movement of the pusherbar to effectuate one of a distal and proximal movement of the advancerplate.

The apparatus may further include a clip follower slidably supported inthe shaft assembly for urging the plurality of surgical clips in adistal direction. The clip follower may include a first tab projectingfrom a first surface thereof and a second tab projecting from a secondsurface thereof. In use, the first tab of the clip follower may engagethe advancer plate as the advancer plate is moved distally such that theclip follower is moved distally to advance the plurality of surgicalclips, and wherein the second tab of the clip follower may engage astationary feature as the advancer plate is moved proximally such thatthe clip follower remains stationary.

The apparatus may further include a clip carrier disposed in the shaftassembly, wherein the clip carrier is configured to retain the pluralityof surgical clips and the clip follower, and wherein the second tab ofthe clip follower may engage features formed in the clip carrier.

The clip follower may be incrementally advanced through the shaftassembly. The clip follower may include a catch extending from a surfacethereof, wherein the catch may engage the pusher bar following firing ofa last surgical clip and may prevent movement of the pusher bar in aproximal direction.

The apparatus may further include a ratchet assembly disposed in thehandle assembly. The ratchet assembly may be prevented from re-settingwhen the pusher bar does not return to a proximal position.

The apparatus may further include a counter supported in the housingassembly. The counter may provide an indication when a surgical clip hasbeen fired.

The apparatus may further include an indicator supported in the housingassembly. The indicator may provide at least one of an audible and atactile indication when at least one of a surgical clip is loaded intothe jaws, a surgical clip is fired and the apparatus is re-set.

The apparatus may further include a wedge plate reciprocally disposedwithin the shaft assembly. The wedge plate may be movable between aposition where a distal end thereof is disposed in the jaws and aposition where the distal end thereof is free from said jaws. The wedgeplate may further include a third spring clip supported thereon forselectively engaging a second feature of the connector plate, whereinthe second feature of the connector plate selectively disengages fromthe third spring clip following an initial distal movement of theconnector plate.

The apparatus may further include a drive bar actuatable by the handleassembly and connected to the connector plate for effecting movement ofthe connector plate. The apparatus may further include a drive channelreciprocally disposed within the shaft assembly, wherein the drive barselectively engages the drive channel to effect translation of the drivechannel. A distal end of the drive channel may engage a surface of thejaws upon distal advancement thereof to effectuate approximation of thejaws.

The drive channel may actuate a wedge lock release upon distaladvancement thereof to cause proximal movement of the wedge plate towithdraw the distal end of the wedge plate from the jaws and permit thedrive channel to approximate the jaws.

The shaft assembly may be rotatable, about the longitudinal axis, withrespect to the handle assembly. The shaft assembly may include a guardsupported therein, wherein the guard may prevent the third spring clipfrom splaying outwardly as the third spring clip translates thereacross.

The wedge plate and/or the drive channel may be biased to a proximalposition.

According to another aspect of the present disclosure, an apparatus forapplication of surgical clips to body tissue is provided. The apparatusincludes a handle assembly; a shaft assembly extending distally from thehandle assembly and defining a longitudinal axis; a plurality ofsurgical clips disposed within the shaft assembly; a jaw mountedadjacent a distal end portion of the shaft assembly, the jaw beingmovable between an open spaced-apart condition and a closed approximatedcondition; and a clip follower slidably supported in the shaft assemblyfor urging the plurality of surgical clips in a distal direction. Theclip follower includes a first tab projecting from a first surfacethereof and a second tab projecting from a second surface thereof. Thefirst tab of the clip follower engages the advancer plate as theadvancer plate is moved distally such that the clip follower is moveddistally to advance the plurality of surgical clips, and the second tabof the clip follower engages a stationary feature as the advancer plateis moved proximally such that the clip follower remains stationary.

The apparatus may further include an advancer plate reciprocallydisposed within the shaft assembly. The advancer plate may define aplurality of windows formed along a length thereof. In use, the firsttab of the clip follower may selectively engage a window of theplurality of windows as the advancer plate reciprocates.

The apparatus may further include a pusher bar reciprocally disposedwithin the shaft assembly. The pusher bar may be configured to load adistal-most surgical clip into the jaws while the jaws are in the opencondition and remain in contact with the loaded surgical clip during anapproximation of the jaws.

The advancer plate may include at least one fin selectively engageableby a shoulder of the pusher bar. The shoulder of the pusher bar mayengage the at least one fin of the advancer plate during a distal and aproximal movement of the pusher bar to effectuate one of a distal andproximal movement of the advancer plate.

The pusher bar may include a pusher formed at a distal end thereof,wherein the pusher has a narrow profile for contacting the loadedsurgical staple at a single location. The pusher may define a plane thatis oriented substantially orthogonal to a plane of the loaded surgicalstaple.

The apparatus may further include a connector plate reciprocallydisposed within the shaft assembly. The connector plate may beselectively connected to the pusher bar. In use, during an initialdistal movement of the connector plate the pusher bar may be distallyadvanced and during a further distal movement of the connector plate theconnector plate may be disconnected from the pusher bar.

The pusher bar may include a first spring clip supported thereon fordetachably connecting to a feature of the shaft assembly when the pusherbar is in an advanced position for maintaining the pusher bar in theadvanced position. The pusher bar may farther include a second springclip supported thereon for detachably connecting to a first feature ofthe connector plate, wherein the first feature of the connector platedisconnects from the second spring clip following the initial distalmovement of the connector plate.

The apparatus may further include a clip carrier disposed in the shaftassembly. The clip carrier may be configured to retain the plurality ofsurgical clips and the clip follower. The second tab of the clipfollower may engage features formed in the clip carrier. The clipfollower may be incrementally advanced through the shaft assembly. Theclip follower may include a catch extending from a surface thereof. Thecatch may engage the pusher bar following firing of a last surgical clipand may prevent movement of the pusher bar in a proximal direction.

The apparatus may further include a ratchet assembly disposed in thehandle assembly. The ratchet assembly may be prevented from re-settingwhen the pusher bar does not return to a proximal position.

The apparatus may further include a counter supported in the housingassembly, wherein the counter may provide an indication when a surgicalclip has been loaded or fired. The apparatus may further include anindicator supported in the housing assembly, wherein the indicator mayprovide at least one of an audible and a tactile indication when atleast one of a surgical clip is loaded into the jaws, a surgical clip isfired and the apparatus is re-set.

The apparatus may further include a wedge plate reciprocally disposedwithin the shaft assembly. The wedge plate may be movable between aposition where a distal end thereof is disposed in the jaws and aposition where the distal end thereof is free from said jaws. The wedgeplate may further include a third spring clip supported thereon forselectively engaging a second feature of the connector plate, whereinthe second feature of the connector plate may selectively disengage fromthe third spring clip following an initial distal movement of theconnector plate.

The apparatus may further include a drive bar actuatable by the handleassembly and connected to the connector plate for effecting movement ofthe connector plate. The apparatus may further include a drive channelreciprocally disposed within the shaft assembly, wherein the drive barmay selectively engage the drive channel to effect translation of thedrive channel, and wherein a distal end of the drive channel may engagea surface of the jaws upon distal advancement thereof to effectuateapproximation of the jaws. The drive channel may actuate a wedge lockplate upon distal advancement thereof to cause proximal movement of thewedge plate to withdraw the distal end of the wedge plate from the jawsand may permit the drive channel to approximate the jaws.

The shaft assembly may be rotatable, about the longitudinal axis, withrespect to the handle assembly. The shaft assembly may include a cuffsupported therein, wherein the cuff may prevent the third spring clipfrom splaying outwardly as the third spring clip translates thereacross.

The wedge plate and/or drive channel may be biased to a proximalposition.

According to a further aspect of the present disclosure an apparatus forapplication of surgical clips to body tissue is provided wherein theapparatus includes a handle assembly and a shaft assembly extendingdistally from the handle assembly and defining a longitudinal axis. Thehandle assembly includes a trigger and a drive bar reciprocallytranslatable by the trigger upon an actuation thereof. The shaftassembly includes a housing; a plurality of surgical clips disposedwithin the housing; a jaw mounted adjacent a distal end portion of thehousing, the jaw being movable between an open spaced-apart conditionand a closed approximated condition; a pusher bar reciprocally disposedwithin the housing, the pusher bar being configured to load adistal-most surgical clip into the jaws while the jaws are in the opencondition and remain in contact with the loaded surgical clip during anapproximation of the jaws; an advancer plate reciprocally disposedwithin the housing, adjacent to the pusher bar, the advancer plateincluding at least one fin selectively engageable by a shoulder of thepusher bar, wherein the shoulder of the pusher bar engages the at leastone fin of the advancer plate during a distal and a proximal movement ofthe pusher bar to effectuate one of a distal and proximal movement ofthe advancer plate; a clip carrier disposed within the housing adjacentthe advancer plate, wherein the clip carrier is configured to retain theplurality of surgical clips; a clip follower slidably supported in theclip carrier at a location proximal of the plurality of surgical clips,the clip follower being configured to urge the plurality of surgicalclips in a distal direction, the clip follower including a first tabprojecting from a first surface thereof and a second tab projecting froma second surface thereof, wherein the first tab of the clip followerengages the advancer plate as the advancer plate is moved distally suchthat the clip follower is moved distally to advance the plurality ofsurgical clips, and wherein the second tab of the clip follower engagesthe clip carrier as the advancer plate is moved proximally such that theclip follower remains stationary; a drive channel reciprocally disposedwithin the housing adjacent the clip carrier, wherein the drive barselectively engages the drive channel to effect translation of the drivechannel, wherein a distal end of the drive channel engages a surface ofthe jaws upon distal advancement thereof to effectuate approximation ofthe jaws; and a wedge plate reciprocally disposed within the housingadjacent the drive channel, the wedge plate being movable between aposition where a distal end thereof is disposed in the jaws and aposition where the distal end thereof is free from said jaws.

The pusher bar may include a pusher formed at a distal end thereof. Thepusher may have a narrow profile for contacting the loaded surgicalstaple at a single location. The pusher may define a plane that isoriented substantially orthogonal to a plane of the loaded surgicalstaple. The pusher bar may include a first spring clip supported thereonfor selectively engaging a feature of the housing of shaft assembly whenthe pusher bar is in an advanced position for selectively maintainingthe pusher bar in the advanced position. The pusher bar may furtherinclude a second spring clip supported thereon for selectively engaginga first feature of the connector plate, wherein the first feature of theconnector plate selectively disengages from the second spring clipfollowing the initial distal movement of the connector plate.

The clip follower may be incrementally advanced through the shaftassembly. The clip follower may include a catch extending from a surfacethereof. In use, the catch may engage the pusher bar following firing ofa last surgical clip and may prevent movement of the pusher bar in aproximal direction.

The handle assembly may further include a ratchet assembly disposedtherein. In use, the ratchet assembly may be prevented from re-settingwhen the pusher bar does not return to a proximal position. The handleassembly may further include a counter supported in the housingassembly, wherein the counter may provide an indication when a surgicalclip has been fired. The handle assembly may still further include anindicator supported therein. The indicator may provide at least one ofan audible and a tactile indication indicating an event. For example,the event may be at least one of a surgical clip is loaded into thejaws, a surgical clip is fired and the apparatus is re-set.

The wedge plate may further include a third spring clip supportedthereon for selectively engaging a second feature of the connectorplate. In use, the second feature of the connector plate may selectivelydisengage from the third spring clip following an initial distalmovement of the connector plate.

The shaft assembly may include a wedge plate lock. In use, the drivechannel may actuate the wedge plate lock upon distal advancement thereofto cause proximal movement of the wedge plate to withdraw the distal endof the wedge plate from the jaws and permit the drive channel toapproximate the jaws.

The shaft assembly may be rotatable, about the longitudinal axis, withrespect to the handle assembly. The shaft assembly may include a cuffsupported in the housing, wherein the cuff prevents the third springclip from splaying outwardly as the third spring clip translatesthereacross.

The wedge plate and/or the drive channel may be biased to a proximalposition.

BRIEF DESCRIPTION OF THE DRAWINGS

The present clip applier will be more fully appreciated as the samebecomes better understood from the following detailed description whenconsidered in connection with the following drawings, in which:

FIG. 1 is a front, perspective view of a surgical clip applier accordingto an embodiment of the present disclosure;

FIG. 2 is a rear, perspective view of the clip applier of FIG. 1illustrating a rotation of a shaft assembly thereof;

FIG. 3 is a front, perspective view of a distal end of the shaftassembly of the clip applier of FIGS. 1 and 2;

FIG. 4 is a top, plan view of the clip applier of FIGS. 1 and 2;

FIG. 5 is a side, elevational view of the clip applier of FIGS. 1 and 2;

FIG. 6 is a perspective view of a handle assembly of the clip applier ofFIG. 1-5, illustrated with a left side housing half-section removedtherefrom;

FIG. 7 is a perspective view of a handle assembly of the clip applier ofFIG. 1-5, illustrated with a right side housing half-section removedtherefrom;

FIG. 8 is a perspective view, with parts separated, of the handleassembly of the clip applier of FIGS. 1-5;

FIG. 8A is a perspective view of the handle assembly of FIGS. 6-8, witha trigger removed therefrom;

FIG. 8B is a perspective view of a feedback member of the handleassembly of FIGS. 6-8;

FIG. 9 is a perspective view, with parts separated, of the shaftassembly of the clip applier of FIGS. 1-5;

FIG. 10 is a right side, front perspective view of the shaft assembly ofFIG. 9, shown in an assembled condition;

FIG. 11 is an enlarged view of the indicated area of detail of FIG. 10;

FIG. 12 is a right side, front perspective view of the shaft assembly ofFIGS. 9-11, shown with an upper housing removed therefrom;

FIG. 13 is an enlarged view of the indicated area of detail of FIG. 12;

FIG. 14 is an enlarged view of the indicated area of detail of FIG. 12;

FIG. 15 is an enlarged view of the indicated area of detail of FIG. 12;

FIG. 16 is a perspective view, with parts separated, of a proximal endof a pusher bar and a snap clip of the shaft assembly of FIGS. 9-15;

FIG. 17 is a bottom, plan view of the shaft assembly of FIGS. 9-15,illustrating the proximal end of the pusher bar and the snap clipdisposed in the upper housing;

FIG. 18 is a right side, front perspective view of the shaft assembly ofFIGS. 9-17, shown with an upper housing and the pusher bar removedtherefrom;

FIG. 19 is an enlarged view of the indicated area of detail of FIG. 18;

FIG. 20 is an enlarged view of the indicated area of detail of FIG. 18;

FIG. 21 is a right side, front perspective view of the shaft assembly ofFIGS. 9-20, shown with an upper housing, the pusher bar and an advancerplate removed therefrom;

FIG. 22 is an enlarged view of the indicated area of detail of FIG. 21;

FIG. 23 is a perspective view, with parts separated, of a clip followerand lock-out plate;

FIG. 23A is a top, perspective view of the assembled clip follower andlock-out plate of FIG. 23;

FIG. 24 is a bottom, perspective view of the clip follower of FIG. 23;

FIG. 25 is a right side, front perspective view of a distal end of theshaft assembly of FIGS. 9-23, shown with an upper housing, the pusherbar, the advancer plate and a clip carrier removed therefrom;

FIG. 26 is a right side, front perspective view of the distal end of theshaft assembly of FIG. 25, shown with an upper housing, the pusher bar,the advancer plate, the clip carrier and a drive channel removedtherefrom;

FIG. 27 is a left side, front perspective view of the shaft assembly ofFIGS. 9-26, shown with an upper housing, the pusher bar, the advancerplate, the clip carrier, the drive channel and a wedge plate removedtherefrom;

FIG. 28 is an enlarged view of the indicated area of detail of FIG. 27;

FIG. 29 is an enlarged view of the indicated area of detail of FIG. 27;

FIG. 30 is a left side, front perspective view of a lower housing of theshaft assembly of FIGS. 9-29;

FIG. 31 is an enlarged view of the indicated area of detail of FIG. 30;

FIG. 31A is an enlarged view of the indicated area of detail of FIG. 30;

FIG. 32 is a longitudinal, cross-sectional view of the clip applier ofFIGS. 1-31A, illustrating the clip applier in an unactuated condition;

FIG. 33 is an enlarged view of the indicated area of detail of FIG. 32;

FIG. 34 is a longitudinal, cross-sectional view of a distal end of theshaft assembly of the clip applier of FIGS. 1-31A;

FIG. 35 is a cross-sectional view as taken through 35-35 of FIG. 34;

FIG. 36 is an enlarged view of the indicated area of detail of FIG. 34;

FIG. 37 is a cross-sectional view as taken through 37-37 of FIG. 36;

FIG. 38 is an enlarged view of the indicated area of detail of FIG. 34;

FIG. 39 is a cross-sectional view as taken through 39-39 of FIG. 38;

FIG. 40 is an enlarged view of the indicated area of detail of FIG. 34;

FIG. 41 is a cross-sectional view as taken through 41-41 of FIG. 40;

FIG. 42 is an enlarged view of the indicated area of detail of FIG. 34;

FIG. 43 is a cross-sectional view as taken through 43-43 of FIG. 42;

FIG. 44 is a longitudinal, cross-sectional view of the clip applier ofFIGS. 1-43, illustrating the clip applier during an initial actuationthereof;

FIG. 45 is an enlarged view of the indicated area of detail of FIG. 44;

FIG. 46 is an enlarged view of the indicated area of detail 36 of FIG.34, during the initial actuation of the clip applier;

FIG. 47 is an enlarged view of the indicated area of detail 40 of FIG.34, during the initial actuation of the clip applier;

FIG. 47A is a top, plan view of the pusher bar, illustrating a movementof the pusher bar during the initial actuation of the clip applier;

FIGS. 47B and 47C are each longitudinal, cross-sectional views of theshaft assembly, illustrating a movement of the wedge plate during theinitial actuation of the clip applier;

FIGS. 48 and 49 are enlarged views of the cross-section taken through41-41 of FIG. 40 of the shaft assembly, during the initial actuation ofthe clip applier;

FIG. 50 is an enlarged view of the indicated area of detail 42 of FIG.34, during the initial actuation of the clip applier;

FIG. 51 is a bottom, left side perspective view of a distal end of theshaft assembly, during the initial actuation of the clip applier;

FIGS. 52-54 are each longitudinal, cross-sectional views of the shaftassembly, illustrating a further movement of the wedge plate during theinitial actuation of the clip applier and a disengagement of a stem of aconnector plate from a snap clip of the wedge plate;

FIG. 55 is a longitudinal, cross-sectional view of the clip applier ofFIGS. 1-54, illustrating the clip applier during a further actuationthereof;

FIG. 56 is an enlarged view of the indicated area of detail of FIG. 55;

FIG. 56A is a right side, perspective view of the shaft assembly, withthe upper housing removed, illustrating a movement of the pusher barduring the further actuation of the clip applier;

FIGS. 56B and 56C are each bottom plan views of the advancer plateillustrating a movement of the advancer plate during the furtheractuation of the clip applier;

FIG. 57 is an enlarged view of the indicated area of detail 36 of FIG.34, during the further actuation of the clip applier;

FIG. 58 is an enlarged view of the indicated area of detail 40 of FIG.34, during the further actuation of the clip applier;

FIGS. 59 and 60 are longitudinal, cross-sectional views of the shaftassembly illustrating a movement of the pusher bar during the furtheractuation of the clip applier, and a connection of a clip supportedthereon to a boss of the upper housing;

FIG. 61 is an enlarged view of the indicated area of detail 40 of FIG.34, during the further actuation of the clip applier;

FIG. 62 is an enlarged view of the indicated area of detail 42 of FIG.34, during the further actuation of the clip applier;

FIG. 63 is a longitudinal cross-sectional view of the shaft assemblyillustrating a movement of the drive bar during a further actuation ofthe clip applier;

FIGS. 64 and 65 are enlarged views of the cross-section taken through41-41 of FIG. 40 of the shaft assembly, during the further actuation ofthe clip applier;

FIG. 66 is a top, left side perspective view of a distal end of theshaft assembly, during the further actuation of the clip applier;

FIGS. 67-69 are longitudinal cross-sectional views of the shaft assemblyillustrating a movement of a connector plate during the furtheractuation of the clip applier;

FIGS. 67A-69A are longitudinal cross-sectional views of the shaftassembly illustrating a movement of a connector plate during the furtheractuation of the clip applier, according to an alternate embodiment ofthe present disclosure;

FIG. 70 is a longitudinal, cross-sectional view of the clip applier ofFIGS. 1-69, illustrating the clip applier during a final actuationthereof;

FIG. 71 is an enlarged view of the indicated area of detail of FIG. 70;

FIG. 72 is an enlarged view of the indicated area of detail 42 of FIG.34, during the final actuation of the clip applier;

FIGS. 73 and 74 are front, perspective views of the distal end of theshaft assembly illustrating an actuation of the jaws during the finalactuation of the clip applier;

FIG. 75 is a perspective view illustrating a surgical clip applied to avessel;

FIG. 76 is an enlarged view of the indicated area of detail 71 of FIG.70, during a release of the trigger of the clip applier;

FIG. 76A is a side, elevational view of the handle assembly during arelease of the trigger following a full actuation thereof;

FIG. 77 is a longitudinal cross-sectional view of the shaft assemblyillustrating a movement of the connector plate during the release of thetrigger;

FIG. 78 is a longitudinal, cross-sectional view of the shaft assemblyillustrating a movement of the pusher bar during the release of thetrigger, and a disconnection of the clip supported thereon from the bossof the upper housing;

FIG. 79 is a right side, perspective view of the shaft assembly, withthe upper housing removed, illustrating a movement of the pusher barduring the release of the trigger;

FIG. 80 is an enlarged view of the indicated area of detail 40 of FIG.34, during the release of the trigger;

FIG. 81 is a longitudinal cross-sectional view of the shaft assemblyillustrating a reconnection of a stem of the connector plate to a snapclip of the pusher bar, during the release of the trigger;

FIGS. 82 and 83 are each longitudinal, cross-sectional views of theshaft assembly, illustrating a movement of the wedge plate during therelease of the trigger and a reengagement of the stem of the connectorplate to a snap clip of the wedge plate;

FIG. 84 is front, perspective view of a distal end of the shaft assemblywhen the clip applier is in a locked-out condition;

FIG. 85 is an enlarged view of the indicated area of detail 42 of FIG.34, when the clip applier is in a locked-out condition; and

FIG. 86 is an enlarged view of the indicated area of detail 71 of FIG.70, when the clip applier is in a locked-out condition.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of surgical clip appliers in accordance with the presentdisclosure will now be described in detail with reference to the drawingfigures wherein like reference numerals identify similar or identicalstructural elements. As shown in the drawings and described throughoutthe following description, as is traditional when referring to relativepositioning on a surgical instrument, the term “proximal” refers to theend of the apparatus which is closer to the user and the term “distal”refers to the end of the apparatus which is further away from the user.

Referring now to FIGS. 1-5, a surgical clip applier in accordance withan embodiment of the present disclosure is generally designated as 100.Clip applier 100 includes a handle assembly 102 and an endoscopicportion including a shaft assembly 104 extending distally from handleassembly 102.

Shaft assembly 104 has an outer diameter of about 10 mm. Shaft assembly104 may have various elongated or shortened lengths depending onintended use, such as, for example, in bariatric surgery.

As seen in FIGS. 1-5, surgical clip applier 100 includes a pair of jaws106 mounted on a distal end of shaft assembly 104 and actuatable by atrigger 108 of handle assembly 102. Jaws 106 are formed of a suitablebiocompatible material such as, for example, stainless steel or titaniumand define a channel 106 a therebetween for receipt of a surgical clip“C” therein. When jaws 106 are in an open or un-approximated conditionrelative to each other, a width of jaws 106 measures greater than anouter diameter of shaft assembly 104.

Jaws 106 are mounted in the distal end of shaft assembly 104 such thatthey are longitudinally stationary relative thereto. A knob 110 may berotatably mounted on a distal end of handle assembly 102 and affixed toshaft assembly 104 to transmit and/or provide 360° rotation to shaftassembly 104 and jaws 106 about a longitudinal axis thereof (see FIG.2).

Referring now to FIGS. 1-8, handle assembly 102 of surgical clip applier100 is shown. Handle assembly 102 includes a housing 103 having a firstor right side half-section 103 a and a second or left side half-section103 b. Handle assembly 102 includes a trigger 108 pivotably supportedbetween right side half-section 103 a and left side half-section 103 b.Handle assembly 102 defines a window 103 c fowled in housing 103 forsupporting and displaying a counter mechanism, as will be discussed ingreater detail below. Housing 103 of handle assembly 102 may be formedof a suitable plastic material.

Housing 103 supports a drive assembly 120 between right sidehalf-section 103 a and left side half-section 103 b. Drive assembly 120includes a wishbone link 122 having a first end pivotally connected totrigger 108, and a second end pivotally connected to a crank plate 124.As seen in FIGS. 6-9, drive assembly 120 further includes a driveconnector 134 rotatably connected to crank plate 124, a plunger 135interconnected to drive connector 134, and a spring 136 supported ondrive connector 134. Plunger 135 defines a longitudinal slot 135 aconfigured and adapted to receive a proximal end of a drive bar 140therein.

Drive bar 140 is connected to plunger 135 via an integral pin 135 b (seeFIG. 9). A cap 144 is provided through which plunger 135 extends. A seal(not shown) is provided to create an air-tight seal between plunger 135and an outer tube 150.

As seen in FIGS. 6-8, handle assembly 102 further includes a rack 124 aformed in/on crank plate 124 such that rack 124 a is movable therewith.Rack 124 a includes a plurality of teeth interposed between a distalrecess 124 b and a proximal recess 124 c defined in crank plate 124.Recesses 124 b and 124 c are provided to allow pawl 224 to reverse andadvance back over the teeth of rack 124 a when crank plate 124 changesbetween proximal and distal movement.

Handle assembly 102 further includes a pawl 224 pivotally connected tohousing 103 by a pawl pin 226 at a location wherein pawl 224 is insubstantial operative engagement with rack 124 a of crank plate 124.Pawl 224 includes a pawl tooth 224 a which is selectively engageablewith the teeth of rack 124 a of crank plate 124. Pawl tooth 224 a isengageable with the rack teeth to restrict longitudinal movement of rack124 a and, in turn, crank plate 124 within handle assembly 102. A pawlspring 228 is provided to bias pawl 224 into operative engagement withrack 124 a of crank plate 124.

As seen in FIGS. 6-8, crank plate 124 is pivotably connected to wishbonelink 122 via a pin 123. Crank plate 124 defines a series of ratchetteeth 124 a formed therein for selective engagement with pawl 224.

As seen in FIGS. 8, 8A and 8B, handle assembly 102 further includes anaudible/tactile feedback member 126 operatively associated with trigger108 so as to rotate together with and about a common axis as trigger 108is actuated. Feedback member 126 defines a race 126 a defining aplurality of ratchets or steps 126 b. A deflectable arm 127 is providedand includes a first end operative connected or disposed in race 126 a,in contact with steps 126 b, of feedback member 126 and a second endconnected to housing 103. In operation, as trigger 108 is actuated, arm127 rides through and/or along race 126 a formed in feedback member 126.As will be discussed in greater detail below, as arm 127 moves oversteps 126 b of feedback member 126, arm 127 snaps over steps 126 b andcreates an audible sound/click and/or a tactile vibration.

Audible/tactile feedback member 126 includes sufficient steps 126 b soas to create an audible/tactile indication after a clip has been fullyloaded into the jaws of surgical clip applier 100, after the loaded cliphas been formed by the jaws of surgical clip applier 100, and whensurgical clip applier 100 is reset to the home position and ready tofire/form another clip.

As seen in FIGS. 6, 7, 8 and 8A, handle assembly 102 of surgical clipapplier 100 further includes a counter mechanism 132 supported inhousing 103 and visible through window 103 c defined in housing 103.Counter mechanism 132 includes a display 132 a, a processor 132 b, andan energy source (not shown) in the form of a battery or the like.

Display 132 a may be any device known in the art to provide anindication of an event. The event may be related to the procedure or theoperation of the clip applier 100. Display 132 a is a liquid crystaldisplay (LCD).

Display 132 a displays one or more operating parameters of clip applier100 to the surgeon. The operating parameter displayed by display 132 aincludes an amount or number of clips remaining, a number of clips thathave been used, a position parameter, a surgical time of usage, or anyother parameter of the procedure.

A Mylar or another polymeric insulating material is disposed betweenbattery or energy source and a contact of processor 132 b which preventsthe battery or energy source from becoming drained during storage. Thetab extends out of housing 103 of surgical clip applier 100 in order toallow for easy removal of the tab therefrom. Once the tab is removed,battery or energy source comes into electrical contact with the contactof processor 132 b and in turn energizes display 132 a.

As seen in FIGS. 6, 7, 8 and 8A, handle assembly 102 of surgical clipapplier 100 further includes a counter actuation mechanism including acounter actuation lever 130 having a first arm 130 a configured andadapted to operatively, selectively engage processor 132 b of countermechanism 132. Counter actuation lever 130 further includes a second arm130 b configured and adapted to operatively, slidably engage a slot 128a formed in an actuator plate 128 slidably supported in housing 103.

In operation, as will be described in greater detail below, as trigger108 is squeezed, trigger 108 causes wishbone link 122 to be advanceddistally, causing crank plate 124 to be advanced distally. When arm 124d of crank plate 124 is advanced a predetermined distance, arm 124 dengages or contacts finger 128 b of actuator plate 128. As crank plate124 is further advanced distally, crank plate 124 forces or pullsactuator plate 128 in a distal direction thereby actuating counteractuation lever 130 to activate counter mechanism 132.

In particular, when actuator plate 128 is moved distally a sufficientdistance, second arm 130 b of counter actuation lever 130 is cammedwithin slot 128 b thereof and rotates counter actuation lever 130resulting in first arm 130 a. When actuator plate 128 is movedproximally a sufficient distance, second arm 130 b of counter actuationlever 130 is returned to a home position resulting in first arm 130 a ofcounter actuation lever 130 disengaging counter mechanism 132.

Turning now to FIGS. 9-31A, shaft assembly 104 of surgical clip applier100 is shown and described hereinbelow. Shaft assembly 104 and thecomponents thereof may be formed of suitable biocompatible materials,such as, for example, stainless steel, titanium, plastics and the like.Shaft assembly 104 includes an outer tube 150 having a proximal end 150a supported within housing 103, a distal end 150 b, and a lumen 150 cextending therethrough. Outer tube 150 is secured within housing 103 bya flange projecting from an outer surface thereof. Shaft assembly 104further includes an upper housing 152 a and a lower housing 152 b, eachdisposed within lumen 150 c of outer tube 150. A rear upper housing 154is disposed within outer tube 150 and proximal of upper housing 152 a.

As seen in FIGS. 9, 12 and 13, shaft assembly 104 further includes apusher bar 156 slidably disposed within upper housing 152 a and a rearupper housing 154. Pusher bar 156 includes a distal end 156 a defining anarrow-profile pusher 156 c configured and adapted to selectivelyengage/move (i.e., distally advance) a distal-most clip “C1” of a stackof clips “C” and to remain in contact with the distal-most clip “C1”during an initial formation thereof. Pusher bar 156 further includes aproximal end 156 b. Pusher bar 156 defines a distal window 156 d havinga catch 156 e, a pair of recesses 156 f located proximal of distalwindow 156 d and formed in each side edge thereof, an elongate slot 156g located proximal of side recesses 156 f, and a proximal-most window156 h located proximal of slot 156 g.

As seen in FIGS. 9 and 14, pusher bar 156 supports a first snap clip 157a along an upper surface thereof at a location distal of side recesses156 f of pusher bar 156. First snap clip 157 a is configured in such amanner that the tines thereof project or are spaced an amount from anupper surface of pusher bar 156.

As seen in FIGS. 9 and 15, pusher bar 156 supports a second snap clip157 b along a lower surface thereof at a location proximal of aproximal-most window 156 h of pusher bar 156. Second snap clip 157 b isoriented in such a manner that the tines thereof project an amountsufficient to overlie proximal-most window 156 h of pusher bar 156. Thetines of second snap clip 157 b are spaced from one another by an amountthat is less than a width of proximal-most window 156 h of pusher bar156.

As seen in FIGS. 9 and 16-20, shaft assembly 104 further includes anadvancer plate 162 reciprocally supported beneath pusher bar 156. Asseen in FIGS. 16 and 17, a fourth snap clip 157 d is supported at aproximal end of advancer plate 162. Snap clip 157 d includes a pair oftines that are detachably connected in proximal retaining grooves 152 mand distal retaining grooves 152 n formed in upper housing 152 a. Inthis manner, in use, snap clip 157 d detachably engage retaining grooves152 m and distal retaining grooves 152 n to maintain advancer plate 162in a proximal or a distal position. Upon distal advancement of advancerplate 162, the tines of snap clip 157 d cam inward and allow advancerplate 162 to continue to move distally.

As seen in FIGS. 18-20, advancer plate 162 includes a series of windows162 a formed therein and extending along a length thereof. As seen inFIG. 19, each window 162 a defines a proximal edge that extends below asurface of advancer plate 162 so as to define a lip or ledge 162 c.Advancer plate 162 further includes a pair of side fin 162 b extendingfrom a side edge thereof, in a direction toward upper housing 152 a. Asseen in FIG. 15, a pair of side fins 162 b are slidably disposed withinside recesses 156 f of pusher bar 156.

As seen in FIGS. 9 and 21-22, shaft assembly 104 further includes a clipcarrier 164 disposed within upper housing 152 a, and beneath advancerplate 162. Clip carrier 164 is generally a box-like structure having anupper wall, a pair of side walls and a lower wall defining a channeltherethrough. Clip carrier 164 includes a plurality of spaced apartwindows 164 a (see FIG. 9) formed in the lower wall and extendinglongitudinally along a length thereof. Clip carrier 164 includes anelongate window formed in the upper wall and extending longitudinallyalong a length thereof.

As seen in FIGS. 9 and 21, a stack of surgical clips “C” is loadedand/or retained within the channel of clip carrier 164 in a manner so asto slide therewithin and/or therealong. The channel of clip carrier 164is configured and dimensioned to slidably retain a stack or plurality ofsurgical clips “C” in tip-to-tail fashion therewithin.

As seen in FIG. 19, a distal end of clip carrier 164 includes a pair ofspaced apart, resilient tangs 164 b. Tangs 164 b are configured andadapted to detachably engage a backspan of a distal-most surgical clip“C1” of the stack of surgical clips “C” retained within clip carrier164.

As seen in FIGS. 9 and 21-24, shaft assembly 104 of clip applier 100further includes a clip follower 166 slidably disposed within thechannel of clip carrier 164. As will be described in greater detailbelow, clip follower 166 is positioned behind the stack of surgicalclips “C” and is provided to urge the stack of clips “C” forward duringan actuation of clip applier 100. As will be described in greater detailbelow, clip follower 166 is actuated by the reciprocating forward andbackward motion of advancer plate 162.

As seen in FIGS. 23, 23A and 24, clip follower 166 includes body portion166 a, a distal tab 166 b extending substantially upwardly andrearwardly from body portion 166 a, and a proximal tab 166 c extendingsubstantially downwardly and rearwardly from body portion 166 a.

Distal tab 166 b of clip follower 166 is configured and dimensioned toselectively engage ledges 162 c of windows 162 a of advancer plate 162.In use, engagement of distal tab 166 b of clip follower 166 againstledges 162 c of windows 162 a of advancer plate 162 causes clip follower166 to incrementally advance or travel distally as advancer plate 162 isadvanced or moved in a distal direction.

Proximal tab 166 c is configured and dimensioned to selectively engagewindows 164 a formed in clip carrier 164. In use, engagement of proximaltab 166 c of clip follower 166 in a window 164 a formed clip carrier 164prevents clip follower 166 from traveling or moving in a proximaldirection.

Clip follower 166 includes a lock-out plate 165 supported thereon oralternatively, integrally formed therewith. Lock-out plate 165 includesa resilient tail 165 a, defining a window 165 b, extending therefrom, ina direction upwardly and rearwardly from body portion 166 a of clipfollower 166.

As seen in FIGS. 9, 25 and 38, shaft assembly 104 further includes adrive channel 168 reciprocally supported in channel assembly 104 at alocation below clip carrier 164. Drive channel 168 is a substantiallyU-shaped channel including a pair of spaced apart side walls 168 bextending from a backspan 168 c thereof, in a direction away from clipcarrier 164 and towards lower housing 152 b. Drive channel 168 furtherincludes a tab 168 d projecting from backspan 168 c, at a locationproximal of slot 168 a, and extending in the direction of side walls 168b. As seen in FIG. 41, drive channel 168 defines a slot or window 168 eformed in one of side walls 168 b for selectively receiving a tooth 194c of wedge plate release 194.

As seen in FIGS. 9 and 25, shaft assembly 104 of clip applier 100includes a drive channel strap 167 secured to drive channel 168. Strap167 is secured to side walls 168 b of drive channel 168 so as to extendtransversely thereacross. Strap 167 is secured to drive channel 168 at alocation distal of elongate slot 168 a. Strap 167 is secured to drivechannel 168 such that wedge plate 172 extends between backspan 168 c ofdrive channel 168 and jaws 106.

As seen in FIGS. 9, 26 and 27, clip applier 100 includes a pair of jaws106 mounted on or at a distal end of shaft assembly 104 and actuatableby trigger 108. Jaws 106 are formed of a suitable biocompatible materialsuch as, for example, stainless steel or titanium.

Jaws 106 are mounted adjacent a distal end of drive channel 168, viabosses formed in lower housing 152 b that engage receiving slots formedin jaws 106, such that jaws 106 are held stationary relative to drivechannel 168. As seen in FIG. 25, jaws 106 define a channel 106 atherebetween for receipt of a surgical clip “C” therein.

As seen in FIGS. 9, 25 and 26, shaft assembly 104 of clip applier 100further includes a wedge plate 172 having a distal end interposedbetween drive channel 168 and jaws 106 and a proximal end extendingthrough shaft assembly 104. Wedge plate 172 includes a substantiallytapered distal end 172 a for selective operative interposition betweenjaws 106. As seen in FIG. 26, wedge plate 172 defines a fin or tab 172 bprojecting from a lower surface thereof. As seen in FIG. 22, wedge plate172 defines a proximal-most slot 172 c formed therein for slidablyreceiving a second stem 174 c of a connector plate 174 therein.

As seen in FIG. 22, a third snap clip 157 c is supported at a proximalend of wedge plate 172. Third snap clip 157 c is oriented in such amanner that the tines thereof project an amount sufficient to overlieproximal-most window 172 c formed in wedge plate 172. The tines of thirdsnap clip 157 c are spaced from one another by an amount that is lessthan a width of proximal-most window 172 c of wedge plate 172.

As seen in FIGS. 9, 18, 20 and 36, shaft assembly 104 of clip applier100 further includes a connector plate 174 slidably interposed betweenpusher bar 156 and wedge plate 172 and detachably connectable to each ofpusher bar 156 and wedge plate 172. Connector plate 174 includes atapered distal end 174 a, a first stem 174 b extending from an uppersurface thereof and a second stem 174 c extending from a bottom surfacethereof. Each stem 174 b, 174 c has a substantially tear-drop shapedprofile wherein a distal end of each stem 174 b, 174 c is larger than aproximal end thereof.

In operation, first stem 174 b of connector plate 174 is configured anddimensioned for detachable connection with second snap clip 157 b thatis secured to pusher bar 156, and second stem 174 c of connector plate174 is configured and dimensioned for detachable connection with thirdsnap clip 157 c that is secured to wedge plate 172.

As seen in FIGS. 22, 36 and 37, second stem 174 c of connector plate 174extends into a window 140 b defined in drive bar 140. In this manner, asdrive bar 140 is also reciprocated, connector plate 174 is reciprocatedtherewith.

As seen in FIG. 31A, a guard 198 is supported in lower housing 152 b ata location so as to maintain the relative distance between the tines ofthe third snap-clip 157 c during an initial distal advancement thereof.In this manner, second stem 174 b of connector plate 174 can notprematurely disengage from third snap clip 157 c until third snap clip157 c has surpassed guard 198.

As seen in FIGS. 9, 27, 29 and 41, shaft assembly 104 of clip applier100 further includes a slider joint 180 slidably supported within achannel of lower housing 152 b. Slider joint 180 includes a body portion182 and a rod 184 extending therefrom. When properly positioned withinthe channel of lower housing 152 b, rod 184 of slider joint 180 extendsin a substantially distal direction. Rod 184 of slider joint 180slidably passes through a stub 152 d formed in and extending from thechannel of lower housing 152 b (see FIG. 29). Shaft assembly 104 furtherincludes a biasing member 186, in the form of a compression spring,supported on rod 184 and interposed between stub 152 d of lower housing152 b and body portion 182 of slider joint 180.

Body portion 182 of slider joint 180 includes a boss 182 a formed near aproximal end thereof, and configured and adapted for slidable engagementin elongate slot 140 a of drive bar 140 (see FIG. 29). Body portion 182of slider joint 180 further includes a pocket 182 b formed near a distalend thereof, and configured and adapted for receiving tab 168 d of drivechannel 168 therein (see FIGS. 38 and 39).

As seen in FIGS. 9, 27 and 28, shaft assembly 104 of clip applier 100further includes a wedge plate lock 190 slidably supported in thechannel of lower housing 152 b and in drive channel 168. Wedge platelock 190 includes a body portion 190 a, a rod 190 b extending distallyfrom body portion 190 a, a tail 190 c extending proximally from bodyportion 190 a, a pocket 190 d formed in an upper surface of body portion190 a, and a stem or tooth 190 e extending from tail 190 c. Shaftassembly 104 further includes a biasing member 192, in the form of acompression spring, supported on rod 190 b and interposed between lowerhousing 152 b of and body portion 190 a of wedge plate lock 190.

Shaft assembly 104 of clip applier 100 further includes a wedge platerelease 194 rotatably supported in the channel of lower housing 152 b.Wedge plate release 194 includes a stem 194 a configured for engagementwith tooth 190 e extending from tail 190 c of wedge lock plate 190, ahammer 194 b extending outwardly from stem 194 a in a direction towardtail 190 c of wedge plate lock 190, and a tooth 194 c extendingoutwardly from stem 194 a in a direction away from tail 190 c of wedgeplate lock 190.

The operation of surgical clip applier 100, to form or crimp a surgicalclip around a target tissue, such as, for example, a vessel, will now bedescribed. With reference to FIGS. 32-43, surgical clip applier 100 isshown prior to any operation or use thereof. As seen in FIGS. 32 and 33,prior to use or firing of clip applier 100, trigger 108 is generally inan uncompressed or unactuated state. As such, crank plate 124 of driveassembly 120 is at a retracted or proximal-most position and thus,plunger 135 and drive bar 140 are also at a retracted position. Whencrank plate 124 is in the retracted position, pawl 224 is disposedwithin distal recess 124 b defined in crank plate 124.

When drive assembly 120 and drive bar 140 are in the retracted position,as seen in FIGS. 35-37, connector plate 174 is located at a retracted orproximal-most position. With connector plate 174 at a retracted orproximal-most position, pusher bar 156 is also at a retracted orproximal-most position and first tear-drop stem 174 b of connector plate174 is disposed at a proximal end of proximal-most window 156 h ofpusher bar 156 and retained in snap-fit engagement in the tines ofsecond snap clip 157 b. Also, with connector plate 174 at a retracted orproximal-most position, wedge plate 172 is also at a retracted orproximal-most position and second tear-drop stem 174 c of connectorplate 174 is disposed at a proximal end of proximal-most window 172 c ofwedge plate 172 and retained in snap-fit engagement in the tines ofthird snap clip 157 c.

As seen in FIGS. 36 and 37, when drive assembly 120 and drive bar 140are in the retracted position, tab 182 a of slider joint 182 is locatedat a distal-most position in elongate slot 140 a of drive bar 140.

As seen in FIGS. 38 and 39, when drive assembly 120 and drive bar 140are in the retracted position, clip follower 166 is located at aproximal-most end of the channel of clip carrier 164, wherein distal tab166 b of clip follower 166 is operatively disposed within aproximal-most window 162 a of advancer plate 162 and proximal tab 166 cis operatively disposed within a proximal-most window 164 a of clipcarrier 164.

With continued reference to FIGS. 38 and 39, when drive assembly 120 anddrive bar 140 are in the retracted position, slider joint 180 is locatedat a proximal-most position and since tab 168 d of drive channel 168 isdisposed within pocket 182 b of slider joint 180, drive channel 168 isalso located at a proximal-most position. As seen in FIGS. 38 and 39,slider joint 180 abuts against a physical stop 152 e (see FIG. 30)projecting from lower housing 152 b.

As seen in FIGS. 40 and 41, when drive assembly 120 and drive bar 140are in the retracted position, wedge plate lock 190 is located at aproximal-most position such that tooth 190 e extending from tail 190 cthereof is disposed proximal of a ramped ledge 152 f formed in lowerhousing 152 b (see FIGS. 30 and 31). As seen in FIG. 41, wedge platelock 190 abuts against a physical stop 152 g projecting from lowerhousing 152 b. Also as seen in FIG. 41, wedge plate release 194 isdisposed in a first position such that tooth 194 c thereof projects intowindow 168 e formed in side wall 168 b of drive channel 168.

As seen in FIGS. 42 and 43, when drive assembly 120 and drive bar 140are in the retracted position, pusher 156 c of pusher bar 156 isdisposed proximal of a backspan of a distal-most clip “C” retained inclip carrier 164. Distal-most clip “C” is retained within the channel ofclip carrier 164 by tangs 164 b thereof. Also, in this position, asdescribed above, wedge plate 172 is located at a proximal-most positionsuch that distal end 172 a thereof is positioned proximal of jaws 106.

As seen in FIG. 43, with drive channel 168 at a proximal-most position,a distal end thereof is disengaged from proximal camming surfaces 106 bof jaws 106.

Turning now to FIGS. 44-54, as trigger 108 is squeezed or actuated fromthe initial position, during a first stage of an initial stroke, trigger108 causes wishbone link 122 to move crank plate 124 in a distaldirection which, in turn, causes drive connector 134 and plunger 135 tomove distally and to move drive bar 140 distally. As plunger 135 ismoved distally, spring 136 is compressed an initial amount.

Simultaneously therewith, as crank plate 124 is moved distally the teethof rack 124 a engage tooth 224 a of pawl 224 as pawl 224 is moved out orrotated of distal recess 124 a of crank plate 124. In this manner, crankplate 124 can not return to a proximal-most position without completinga full distal stroke.

As seen in FIG. 44, as trigger 108 is squeezed an initial amount, arm127 begins to translate through race 126 a of feedback member 126.

As seen in FIG. 46, as drive bar 140 is moved in a distal direction,drive bar 140 pushes connector plate 174 in a distal direction. Sincepusher bar 156 is selectively connected to connector plate 174 viasecond snap clip 157 b, pusher bar 156 is advanced or pulled in a distaldirection. Also, since wedge plate 172 is selectively connected toconnector plate 174 via third snap clip 157 c, wedge plate 172 is alsoadvanced or dragged in a distal direction.

As drive bar 140 is moved in the distal direction, elongate slot 140 athereof is also moved in a distal direction such that tab 182 a ofslider joint 182 is translated in a proximal direction relative thereto.

As seen in FIG. 47-49, as wedge plate 172 is moved in a distaldirection, since tab 172 b of wedge plate 172 is retained in pocket 190d of wedge plate lock 190, wedge plate lock 190 is moved or dragged in adistal direction causing tooth 190 e of tail 190 c thereof to cam overramped ledge 152 f formed in lower housing 152 b, thereby moving from aposition proximal of ramped ledge 152 f to a position distal of rampedledge 152 f. As wedge plate lock 190 is moved in a distal direction,biasing member 192 is compressed an initial amount. As seen in FIG. 49,wedge plate lock 190 is moved in a distal direction until wedge platelock 190 abuts against a physical stop formed in lower housing 152 b.

As seen in FIG. 47A, as pusher bar 156 is moved in a distal direction,fins 162 b of advancer plate 162 translate, a predetermined distance,within side recesses 156 f of pusher bar 156 until fins 162 b contact orengage a proximal end of side recesses 156 f of pusher bar 156.

As seen in FIGS. 47B and 47C, as wedge plate 172 is moved in the distaldirection, due to the connection of second stem 174 c of connector plate174 with third snap clip 157 c, second stem 174 c of connector plate 174is prevented from prematurely disconnecting from third snap clip 157 cby guard 198. In particular, guard 198 acts on the tips of the tines ofthird snap clip 157 c to prevent the tines from splaying outward due tothe forces acting thereon by the distal forces generated by second stem174 c as connector plate 174 is moved in the distal direction.

As seen in FIG. 50, as pusher bar 156 is moved in a distal directionpusher 156 c thereof engages a backspan of a distal-most clip “C” andbegins to urge distal-most clip “C” in a distal direction. As pusher bar156 moves distal-most clip “C” in a distal direction, distal-most clip“C” snaps out from behind tangs 164 b of clip carrier 164 and begins toenter into channels 106 a of jaws 106.

As seen in FIG. 51, as wedge plate 172 is moved in a distal direction,distal end 172 a thereof enters between jaws 106 causing jaws 106 tosplay outwardly.

Wedge plate 172 is prevented from further movement in the distaldirection, as seen in FIGS. 52-54, once wedge plate lock 190 abutsagainst the physical stop formed in lower housing 152 b. However, drivebar 140 continues to move connector plate 174 in a distal direction.Since connector plate 174 is continued to be forced distally, once thetips of the tines of third snap clip 157 c move distally beyond guard198, the forces acting on second stem 174 c are sufficient to cause thetines of third snap clip 157 c to splay outward and allow second stem174 c to snap out from therebetween thereby allowing for connector plate174 to continue to move in a distal direction.

Turning now to FIGS. 55-69, as trigger 108 is further squeezed oractuated from the first stage of the initial stroke through a secondstage of the initial stroke, trigger 108 causes wishbone link 122 tofurther move crank plate 124 in a distal direction which, in turn,causes drive connector 134 and subsequently plunger 135 to further movedistally and to further move drive bar 140 distally. As plunger 135 ismoved distally, spring 136 is compressed a further amount.

Simultaneously therewith, as crank plate 124 is moved distally the teethof rack 124 a thereof move further proximally with respect to tooth 224a of pawl 224. As such, crank plate 124 still can not return to aproximal-most position without completing a full distal stroke.

As seen in FIG. 55, as crank plate 124 is moved distally, after apredetermine distance, arm 124 d thereof engages or contacts finger 128b of actuator plate 128. As crank plate 124 is further advanceddistally, crank plate 124 forces or pulls actuator plate 128 in a distaldirection thereby actuating counter actuation lever 130 to activatecounter mechanism 132.

In particular, when actuator plate 128 is moved distally a sufficientdistance, second arm 130 b of counter actuation lever 130 is cammedwithin slot 128 b thereof and is urged to rotate resulting in first arm130 a of counter actuation lever 130 engaging counter mechanism 132 andthereby effectuating a change in the display thereof. In particular, thedisplay, which displays the number of clips remaining in surgical clipapplier 100, will reduce by one. Alternatively, the clip countermechanism will increment by one or produce some other change.

As trigger 108 is squeezed further, arm 127 continues to translatethrough race 126 a of feedback member 126. At this point in thesqueezing of trigger 108, a surgical clip is loaded into the jaws 106.Accordingly, arm 127 will interact with a step 126 b formed in race 126a of feedback member 126 and create an audible/tactile indicationadvising the user that a clip has been loaded into the jaws.

As seen in FIG. 57, as drive bar 140 is moved further in a distaldirection, drive bar 140 continues to push connector plate 174 in adistal direction. Since pusher bar 156 is still selectively connected toconnector plate 174 via second snap clip 157 b, pusher bar 156 isfurther advanced or dragged in the distal direction. However, sincethird snap clip 157 c of wedge plate 172 is disconnected from secondstem 174 c of connector plate 174, wedge plate 172 is not furtheradvanced or dragged in the distal direction.

As seen in FIGS. 56A to 56C, as pusher bar 156 is continued to be movedin a distal direction, with the pair of fins 162 b of advancer plate 162engaged by the proximal end of side recesses 156 f of pusher bar 156,pusher bar 156 advances or drags advancer plate 162 in a distaldirection.

As seen in FIGS. 56B and 56C, as advancer plate 162 is advanceddistally, snap clip 157 d disengages proximal retaining grooves 152 mand engages distal retaining grooves 152 n formed in upper housing 152a.

As seen in FIG. 57, drive bar 140 is moved in the distal direction untiltab 182 a of slider joint 182 is relatively translated to aproximal-most position in elongate slot 140 a of drive bar 140.

As pusher bar 156 continues to move in a distal direction, pusher bar156 continues to urge advancer plate 162 in a distal direction via fins162 b. As seen in FIG. 58, as advancer plate 162 is moved in a distaldirection, distal tab 166 b of clip follower 166 is engaged by aproximal edge of a window 162 a receiving distal tab 166 b of clipfollower 166 in order to urge clip follower 166 in a distal direction,relative to clip carrier 164, and thereby advance the stack of clips “C”by an incremental amount. As clip follower 166 is moved in a distaldirection, proximal tab 166 c thereof is caused to be advanced distally,one window 164 a, from a relatively proximal window 164 a of clipcarrier 164 to a relatively distal window 164 a of clip carrier 164.

As seen in FIGS. 58-60, as pusher bar 156 is moved in a distaldirection, first snap clip 157 a, supported on pusher bar 156, snapsonto boss 152 h of upper housing 152 a, thus maintaining pusher bar 156in a forward position.

Additionally, as seen in FIG. 61, as pusher bar 156 continues to move ina distal direction, the stack of clips “C” is caused to move in a distaldirection.

As seen in FIG. 62, as pusher bar 156 is moved in a distal directionpusher 156 c thereof continues to move a distal-most clip “C1” in adistal direction until distal-most clip “C1” completely enters intochannels 106 a of jaws 106. In operation, pusher 156 c of pusher bar 156remains in contact with the backspan of the loaded clip “C” during theformation of said clip “C” in order to provide stability thereto and tomaintain the proper position thereof.

As seen in FIG. 63, as drive bar 140 is moved further in the distaldirection, shoulders 140 c thereof contact a proximal-most end of drivechannel 168. In this manner, as drive bar 140 is moved further in thedistal direction, drive bar 140 moves or urges drive channel 168 in thedistal direction.

As seen in FIG. 64, as drive channel 168 is moved in a distal direction,a proximal edge of window 168 e formed in side wall 168 b of drivechannel 168 contacts against tooth 194 c of wedge plate release 194causing wedge plate release 194 to rotate. As wedge plate release 194rotates, hammer 194 b thereof, presses against tooth 190 e of wedgeplate lock 190 to urge or kick tooth 190 e out from behind ramped ledge152 f. In so doing, as seen in FIG. 65, biasing member 192 is permittedto decompress thus moving wedge plate lock 190 in a proximal direction.As seen in FIG. 66, as wedge plate lock 190 is moved in a proximaldirection, and since wedge plate 172 is connected thereto, wedge plate172 is moved in a proximal direction to withdraw distal end 172 athereof out of engagement from jaws 106.

As seen in FIGS. 58 and 67-69, since pusher bar 156 is maintained in thedistal position by the connection of first snap clip 157 a with boss 152h, as drive bar 140 is moved further in a distal direction, the forcesacting on connector plate 174 cause second snap clip 157 b to disengagefrom first stem 174 b of connector plate 174 thereby allowing forconnector plate 174 to continue to move in a distal direction.

As seen in FIGS. 67A-69A, in an embodiment, the tips of the tines ofsecond snap clip 157 b may be configured to project outwardly so as toengage a surface of rear upper housing 154 (see FIG. 9), therebypreventing premature disengagement of second snap clip 157 b from firststem 174 b of connector plate 174. In this embodiment, recesses may beformed in the surfaces of rear upper housing 154 coinciding withlocations at which the tines of second snap clip 157 b may splay outwardthus allowing first stem 174 b of connector plate 174 to disengage an tocontinue to move in a distal direction.

As seen in FIGS. 70-75, as trigger 108 is actuated through a final stageof the initial stroke, trigger 108 causes wishbone link 122 to furthermove crank plate 124 in a distal direction which, in turn, causes driveconnector 134 and plunger 135 to further move distally and to furthermove drive bar 140 distally. As drive connector 134 is moved distally,spring 136 is compressed a further amount.

Simultaneously therewith, as crank plate 124 is moved distally the teethof rack 124 a thereof move further proximally with respect to tooth 224a of pawl 224 to a position where the teeth of rack 124 a disengage fromtooth 224 a of pawl 224 as tooth 224 a of pawl 224 enters proximalrecess 124 c of crank plate 124 and thus resets itself. As such, crankplate 124 may return to a proximal-most position upon a release oftrigger 108.

As seen in FIGS. 72-74, during the final stage of the initial stroke oftrigger 108, drive channel 168 and strap 167 are moved in a distaldirection relative to jaws 106 such that a distal edge of drive channel168 engages against camming surfaces 106 b of jaws 106 causing jaws 106to close and form the clip “C1” positioned therebetween. As seen in FIG.74, pusher 156 c of pusher bar 156 remains at a distal position, incontact with a backspan of said clip “C” during the formation thereof.

As seen in FIG. 55, as trigger 108 is squeezed a final amount, arm 127continues to translate through race 126 a of feedback member 126. Atthis point in the squeezing of trigger 108, surgical clip “C1” has beenfully formed by jaws 106. Accordingly, arm 127 will interact withanother step 126 b formed in race 126 a of feedback member 126 andcreate an audible/tactile indication advising the user that surgicalclip “C1” has been formed by jaws 106.

As seen in FIG. 75, surgical clip “C1” may be formed or crimped onto avessel “V” or any other biological tissue.

Turning now to FIGS. 76-84, the operation of clip applier 100 as trigger108 is returned to an un-squeezed or unactuated position, is shown. Asseen in FIG. 76, as the trigger is returned to the un-squeezed position,the spring is permitted to uncompress, thus urging crank plate 124 tomove in a proximal direction which, in turn, causes the plunger to moveproximally and to move the drive bar proximally. Since pawl 224 has beenreset, crank plate 124 is now permitted to move proximally until tooth224 a of pawl 224 re-enters the distal recess of crank plate 124.

As seen in FIG. 76A, as crank plate 124 is moved proximally, arm 124 dthereof disengages finger 128 b of actuator plate 128 allowing actuatorplate 128 to move in a proximal direction. As actuator plate 128 ismoved proximally, second arm 130 b of counter actuation lever 130 iscammed within slot 128 b thereof and is urged to rotate resulting infirst arm 130 a of counter actuation lever 130 disengaging from countermechanism 132.

As seen in FIG. 77, as drive bar 140 is moved in a proximal direction,drive bar 140 pulls on connector plate 174, via first stem 174 b. Asconnector plate 174 is moved in a proximal direction, first stem 174 bengages the tines of second snap clip 157 h and urges pusher bar 156 ina proximal direction via second snap clip 157 b.

As seen in FIG. 78, as forces act on pusher bar 156 to move pusher bar156 in a proximal direction, said forces overcome the retention force offirst snap clip 157 a with boss 152 h of upper housing 152 a, thusreleasing first snap clip 157 a from boss 152 h and allowing pusher bar156 to move in the proximal direction.

As seen in FIG. 79, as pusher bar 156 continues to move in the proximaldirection, a distal end of side recesses 156 f thereof engage fins 162 bof advancer plate 162 and cause advancer plate 162 to move in a proximaldirection. As pusher bar 156 moves in the proximal direction, pusher barnose 156 c snaps behind a distal-most clip of the remaining stack ofclips “C” and thus becomes the new distal-most clip “C1.”

As seen in FIG. 80, as advancer plate 162 is moved in a proximaldirection, proximal tab 166 c of clip follower 166 engages a proximaledge of a window 164 a of clip carrier 164 in order to maintain therelative position of clip follower 166 in clip carrier 164. As advancerplate 162 is moved in a proximal direction, distal tab 166 b thereof iscaused to be advanced distally, one window 162 a, from a relativelyproximal window 162 a of advancer plate 162 to a relatively distalwindow 162 a of advancer plate 162.

As seen in FIG. 81, when pusher bar 156 stops its proximal movement,upon engagement thereof with a boss protruding from an inner surface ofupper housing half 152 a, continued proximal movement of connector plate174 will cause first stem 174 b to re-engage with second snap clip 157b. With proximal movement of pusher bar 156 stopped, continued proximalmovement of connector plate 174 will cause first stem 174 b to re-engagewith second snap clip 157 b.

As seen in FIGS. 82 and 83, as connector plate 174 is moved in aproximal direction, as a result of the proximal movement of drive bar140, second stem 174 c engages the tines of third snap clip 157 c andurges wedge plate 172 in a proximal direction via third snap clip 157 c.As wedge plate 172 is moved in a proximal direction, wedge plate lock190 is moved in a proximal direction until wedge plate lock 190 contactsa physical stop in lower housing half 152 b, thereby stopping proximalmovement of wedge plate 172. Once the tips of the tines of third snapclip 157 c move proximally past guard 198, when wedge plate 172 stopsits proximal movement, continued proximal movement of connector plate174 will cause second first stem 174 c to re-engage with third snap clip157 c.

When trigger 108 is returned to the unactuated position, arm 127 willtranslate through race 126 a of feedback member 126 and interact withanother step 126 b formed in race 126 a of feedback member 126 andcreate an audible/tactile indication advising the user that surgicalclip applier 100 has been reset and is ready to fire again.

Turning now to FIGS. 84-85, the configuration of surgical clip applier100, following application of the last surgical clip “C”, is shown. Asseen in FIGS. 84 and 85, when the last surgical clip has been advancedand formed, with pusher bar 156 still in an advanced or distal position,clip follower 166 has been incrementally advanced, by indexer plate 158,an amount sufficient that lock-out plate 165 thereof biases upwardlythrough a window 162 a of advancer plate 162 and into distal window 156d of pusher bar 156. Positioning of lock-out plate 165 in distal window156 d of pusher bar 156 allows for the catch 156 e thereof to enter andengage in window 165 b of lock-out plate 165. In this manner, since clipfollower 166 is maintained in the distal position by proximal tab 166 cthereof engaging in distal window 164 a of clip carrier 164, lock-outplate 165 engages catch 156 e of pusher bar 156 and prevents pusher bar156 from returning to a proximal-most position to reset pawl 224.

Since pusher bar 156 can not or is prevented from moving to its fullyproximal position, as seen in FIG. 86, pawl 224 remains engaged withrack 124 a of crank plate 124 and is not permitted to enter proximalrecess 124 c and thus reset itself. Since pawl 224 can not reset itself,crank plate 124 is locked or stopped from distal or proximal movement.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variances.The embodiments described with reference to the attached drawing figuresare presented only to demonstrate certain examples of the disclosure.Other elements, steps, methods and techniques that are insubstantiallydifferent from those described above and/or in the appended claims arealso intended to be within the scope of the disclosure.

1. An apparatus for application of surgical clips to body tissue, theapparatus comprising: a handle assembly including a trigger and a drivebar reciprocally translatable by the trigger upon an actuation thereof;a shaft assembly extending distally from the handle assembly anddefining a longitudinal axis, the shaft assembly including: a housing; aplurality of surgical clips disposed within the housing; a jaw mountedadjacent a distal end portion of the housing, the jaw being movablebetween an open spaced-apart condition and a closed approximatedcondition; a pusher bar disposed within the housing for reciprocalmovement between proximal and distal positions, the pusher bar beingconfigured to load a distal-most surgical clip into the jaws while thejaws are in the open condition and remain in the distal position duringan approximation of the jaws, the pusher bar including a first springclip supported thereon for detachably connecting to a stationary featureof the housing for maintaining the pusher bar in the distal position; anadvancer plate disposed within the housing for reciprocal movementbetween proximal and distal positions, wherein the advancer plate isengaged by the pusher bar during a distal and a proximal movement of thepusher bar to effectuate one of a distal and proximal movement of theadvancer plate; and a wedge plate disposed within the housing forreciprocal movement between proximal and distal positions, wherein adistal end of the wedge plate is disposed in the jaws when in the distalposition and a the distal end thereof is free from the jaws when in theproximal position.
 2. The apparatus according to claim 1, wherein theadvancer plate includes a spring clip supported thereon for detachablyengaging a stationary feature of the housing to maintain the advancerplate in the distal position.
 3. The apparatus according to claim 1,wherein the stationary feature of the housing blocks distal movement ofthe pusher bar beyond an initial distal movement thereof.
 4. Theapparatus according to claim 1, wherein the connection of the firstspring clip of the pusher bar and the stationary feature of the housingmaintains the pusher bar at the distal position thereof during a firingof the apparatus.
 5. The apparatus according to claim 1, wherein theshaft assembly further includes a connector plate slidably interposedbetween the pusher bar and the wedge plate, the connector plate beingdetachably connectable to each of the pusher bar and the wedge plate. 6.The apparatus according to claim 5, wherein the pusher bar furtherincludes a second spring clip supported thereon for detachablyconnecting to a first feature of the connector plate, wherein the firstfeature of the connector plate disengages from the second spring clipfollowing completion of an initial distal joint movement of theconnector plate and the pusher bar.
 7. The apparatus according to claim5, wherein the wedge plate includes a spring clip supported thereon fordetachably connecting to a second feature of the connector plate,wherein the second feature of the connector plate disengages from thespring clip of the wedge plate following completion of an initial distaljoint movement of the connector plate and the wedge plate.
 8. Theapparatus according to claim 5, wherein the connector plate detachablyconnects to each of the pusher bar and the wedge plate during at least aportion of a firing stoke of the apparatus.
 9. The apparatus accordingto claim 6, wherein the first feature of the connector plate disconnectsfrom the second spring clip of the pusher bar upon continued distalmovement beyond an initial distal movement of the pusher bar.
 10. Theapparatus according to claim 7, wherein the second feature of theconnector plate disconnects from the spring clip of the wedge platefollowing an initial distal movement of the wedge plate.
 11. Theapparatus according to claim 5, wherein the pusher bar and the wedgeplate each disconnect from the connector plate following a respectiveinitial distal movement of each of the pusher bar and the wedge plate.12. The apparatus according to claim 11, wherein each of the pusher barand the wedge plate re-connect with the connector plate upon arespective proximal movement thereof.
 13. The apparatus according toclaim 1, wherein the shaft assembly includes a clip carrier disposedwithin the housing adjacent the advancer plate, wherein the clip carrieris configured to retain the plurality of surgical clips.
 14. Theapparatus according to claim 13, wherein the shaft assembly includes aclip follower slidably supported in the clip carrier at a locationproximal of the plurality of surgical clips, the clip follower beingconfigured to urge the plurality of surgical clips in a distaldirection, the clip follower including a first tab projecting from afirst surface thereof and a second tab projecting from a second surfacethereof, wherein the first tab of the clip follower engages the advancerplate as the advancer plate is moved distally such that the clipfollower is moved distally to advance the plurality of surgical clips,and wherein the second tab of the clip follower engages the clipfollower as the advancer plate is moved proximally such that the clipfollower remains stationary.
 15. The apparatus according to claim 13,wherein the shaft assembly includes a drive channel reciprocallydisposed within the housing adjacent the clip carrier, wherein the drivebar selectively engages the drive channel to effect translation of thedrive channel, wherein a distal end of the drive channel engages asurface of the jaws upon distal advancement thereof to effectuateapproximation of the jaws.
 16. The apparatus according to claim 15,wherein the wedge plate is disposed adjacent the drive channel.
 17. Theapparatus according to claim 14, wherein the clip follower isincrementally advanced through the shaft assembly.
 18. The apparatusaccording to claim 14, wherein the clip follower includes a catchextending from a surface thereof, wherein the catch engages the pusherbar following firing of a last surgical clip and prevents movement ofthe pusher bar in a proximal direction.
 19. The apparatus according toclaim 1, wherein the handle assembly further includes a ratchet assemblydisposed therein, wherein the ratchet assembly is prevented fromre-setting when the pusher bar does not return to a proximal position.20. The apparatus according to claim 15, wherein the shaft assemblyincludes a wedge plate lock, wherein the drive channel actuates thewedge plate lock upon distal advancement thereof to cause proximalmovement of the wedge plate to withdraw the distal end of the wedgeplate from the jaws and permit the drive channel to approximate thejaws.